1. Field of the Invention
The present invention relates to a distributed radar data processing system for processing radar data obtained from a radar device in an air traffic control radar system, and particularly to a technology for distributed processing of radar data.
2. Description of the Related Art
A conventionally-known air traffic control radar system carries out air traffic control by first transmitting signals having a predetermined frequency from a radar device, receiving reflected waves, the return transmitted signals reflected from a plane, and detecting the traveling direction and speed of the plane. An example of such air control radar system is disclosed in Japanese Patent Laid-Open Publication No. Heisei7-5248 as a three dimensional imaging radar that is switched between two operating frequencies, that improves reception of weak signals, and that has improved signal processing capabilities and processing efficiency.
As shown in FIG. 1, for example, a conventional air traffic control radar system includes a radar device 100, a radar data processing system (RDPS) 200, and a plurality of consoles/display devices 300, and thus is called a centralized system.
The radar device 100 is configured by an antenna, a transmitter, a receiver, and a target detector which are not illustrated. The transmitter transmits radio waves through the antenna towards a target. The transmitted waves are reflected from the target and the receiver receives the reflected waves by the antenna and generates received signals. The received signals are transmitted to the radar data processing system 200 as radar data.
The radar data processing system 200 is configured by, for example, a single high performance electronic computer which incorporates software to realize various functions such as tracking, flight plan, display, and control operation. The radar data processing system 200 transmits a processing result of radar data from the radar device 100 to the consoles/display devices 300 to allow them to display the result, and receives signals from the consoles/display devices 300 to control the radar device 100.
As stated above, the consoles/display devices 300 display an image of a detected target based upon a processing result of radar data transmitted from the radar data processing system 200, generates signals in response to console operations by an operator, and send the signals to the radar data processing system 200. The radar data processing system 200 controls the radar device 100 in accordance with the signals transmitted from the consoles/display devices 300.
Since a conventional air traffic control radar system is constructed as a centralized system as described earlier, a failure of the electronic computer configuring the radar data processing system 200 disables the entire air traffic control radar system. In order to deal with such a situation, an air traffic control radar system generally is provided with a redundant system.
Incidentally, in the present day, the universal level of maintenance for air traffic control radar systems has reached a certain point and they are now in the so-called conversion phase. However, in order to convert a conventional air traffic control radar system into a high performance and high functionality air traffic control radar system to meet client's specifications without changing the centralized system itself, it is necessary to change an operating system (OS), a special interface or peripherals. As a result, development of new software will be required for such changes, which makes the air traffic control radar system more expensive.
Moreover, since an electronic computer used in the radar data processing system works only with a particular platform (operating system or hardware), it is not flexible enough to adopt expansion or reduction of an air traffic control radar system. Therefore, the same problem as above will occur again in the event of the next conversion.
Accordingly, there has been a demand for development of a radar data processing system that is not affected by platforms, that enables a non-high performance electronic computer to work, that can meet clients' various specifications, that is flexible enough to deal with expansion and reduction of a radar system, and that is manufactured in a short period of time and inexpensive.